Average growth rates of over seven percent make aerospace one of the global growth branches. DMG MORI supports OEMs and suppliers with productive manufacturing processes thus participating to a disproportionally high degree in the growth of this sector. In order to meet the high requirements of demanding users DMG MORI concentrates its entire expertise in the DMG MORI Aerospace Excellence Center. The machine tool manufacturer offers its customers far more than simply excellent high-tech machines and outstanding technological performance. The DMG MORI experts are being involved in the future projects of customers at an ever earlier stage. This results in the development of optimum manufacturing processes and complete turnkey solutions.

“Sales of several hundred million euros certainly make us the leader in the aerospace sector where machining is concerned. It is our aim to double this figure over the next few years”, says Michael Kirbach, Head of the DMG MORI Aerospace Excellence Center, with a view to the future. In the year 2016 alone DMG MORI sold around 450 machines in this market in 25 countries. Early involvement in customer projects is a basic condition here for developing production solutions that have a promising future.

A prime example of such a future-oriented field is the additive manufacturing of metallic materials. This is currently in the fast lane, especially in the aerospace sector. DMG MORI has been offering a unique hybrid solution with laser deposition welding using a powder nozzle and integrated machining since 2013 and since this year has added selective laser melting in a powder bed as well, a process that is already being used by many manufacturers for “flying” components. “This makes us one of the few suppliers offering not one but two alternative processes, with each one covers a special component segment. We see ourselves therefore as a full-liner with the entire expertise in this sector”, states Michael Kirbach. Additive manufacturing demands a profound knowledge of the processes in order to produce highly complex components with maximum process reliability and reproducibly on an industrial scale. “On principle additive processes also require a digital process chain - from the idea to final measuring of the workpiece.”

Competence partner for all component sizes and materials

“In the DMG MORI Aerospace Excellence Center we support our customers from the feasibility analysis to profitability assessments and on to installation of the machines including customised application technology and an extensive aftersales service”, is how Michael Kirbach describes the service portfolio. The time scale here, from the first enquiry until acceptance of the project, can take anything up to two or even three years. “Our service commitment applies equally for the entire DMG MORI portfolio, of course - from turning and milling to the integration of technologies and on through to include ULTRASONIC, LASERTEC and ADDITIVE MANUFACTURING.”

DMG MORI’s ambitious growth targets require a dynamic market. But air traffic is booming and so, of course, is the sale of aircraft. Leading aircraft manufacturers such as Airbus and Boeing, for example, expect the aircraft fleet to more than double by 2036. A large passenger plane is made up of over three million components. Capacities must therefore be expanded enormously if this demand is to be met. In contrast to its competitors, DMG MORI covers by far the majority of the different workpieces with its manufacturing solutions.

The machine tool manufacturer also benefits from the work in the DMG MORI Aerospace Excellence Center on a technological level, explains Michael Kirbach: “Due to the fact that our experts are involved very early on in the development of customer products, we gain a lot of important experience as well as extensive knowledge. Both are incorporated directly in the development of new machines and components in close dialogue with the design engineers in the DMG MORI production plants – for example where it is a question of the efficient machining of special aerospace materials. We have been pursuing this strategy consistently for over 20 years.”

Lightweight construction is the dominating topic

Aircraft are getting lighter and more efficient – in particular due to new materials. New materials in turn open up undreamt of freedoms in the design of components. The structural parts of aircraft contribute greatly to the total mass, so there is an increasing tendency to use CRP and titanium for such parts in addition to aluminium. The low density of the materials plus their high degree of stability enable advanced geometries such as thin-walled components, for example. This also applies in the construction of engines, where titanium alloys and especially increasingly heat-resistant nickel alloys play a key role.

The choice of material alone indicates just how application-specific a manufacturing solution has to be”, stresses Michael Kirbach in connection with lightweight constructions. In particular, the volume of chips produced during the machining of aluminium from the solid is a challenge – up to 90 percent of the raw material often has to be removed. The machining of titanium components, on the other hand, demands machines designed especially for heavy-duty metal removal. “It is exactly in the question of the material where our customers benefit from our enormous range of machines and technologies. Highly dynamic horizontal centres and our new gantry machines for aluminium and CRP/GRP components, duoBLOCK machines for the high-speed milling of titanium are just as much part of the portfolio as mill-turn or turn-mill machines for the 5-axis machining of rotationally symmetric workpieces in just a few setups in engine construction, for example.” There is virtually no component for which DMG MORI cannot offer a manufacturing solution.

Aerospace speedMASTER 30,000

Their optimum chip fall make horizontal machining centres such as the DMC 80 H linearfrom DMG MORI the ideal solution for the high chip volume involved in the machining of aluminium.

The topics speed, acceleration und jolting are decisive for aluminium. The machines in the DMC H linear series for horizontal machining with their steeply angled interior covers and open-bottom machine beds enable direct chip fall. Combined with high-pressure cooling and the right machining strategy this results in a high level of process stability, longer tool lives as well as optimum heat dissipation and surface qualities of the machined parts. Michael Kirbach sums up: “In a nutshell, we offer an ideal complete package for the machining of structural components made of aluminium: highly dynamic linear drives with 1 g acceleration for more complex geometries, our swivel rotary table and our newly developed aerospace speedMASTER 30,000 for up to 8 l/min metal removal rate for aluminium.

Gantry series expanded

The DMU 200 Gantry from DMG MORI impressively combines large part machining with maximum dynamics

DMG MORI has developed the Gantry series for the dynamic machiningof larger components. The DMU 200 Gantry impressively combines the machining of large parts with maximum dynamics with workpiece weights up to 10,000 kg and 0.5 g acceleration. The DMU 600 G linearhas a work area of 6,000 x 4,500 x 2,000 mm making it predestined for large integral components. With regard to component size the DMU 340 Gantry operates with a work area of 3,400 × 2,800 × 1,250 mm between the two sister machines – whereby the machine can be expanded to up to 6,000 mm in the X-axis and 1,500 mm in the Z-axis.

Efficient milling with ULTRASONIC

The fibre structure and hard-brittle property of CRP materials present a challenge for every type of conventional machining. That is why ULTRASONIC-supported milling is the answer here. The additional oscillation of the tool with up to 10 µm and 20 to 50 kHz mean higher cutting speeds can be achieved with lower temperature impact. At the same time the fibres are cut better and this adds up to a reduction in fibre splitting and delamination. The formation up of built-up edges on the tool due to the adherence of carbon fibre powder is also prevented.

Sturdy machine design for the machining of titanium

As one of many models in the duoBLOCK series, the DMC 80 FD duoBLOCK impresses with its pallet changer through maximum efficiency in mill-turn complete machining – also available with the technology integration grinding on request.

The machining of titanium requires maximum rigidity and performance. DMG MORI relies on its duoBLOCK machining centres for high-speed milling with five axes when it comes to the production of complex titanium components, such as landing gear components of aircraft, for example. “For over 18 years now this concept has been used mainly by our customers in the aerospace industry for hard to machine materials and has been consistently further developed in line with the continuously rising demands”, says Michael Kirbach of DMG MORI’s the many years of experience. “Customers even speak of today’s 4th generation as the benchmark, which of course makes us as machine builders especially proud.” From the DMU 60 P duoBLOCK to the DMU 160 P duoBLOCK, the series offers space for a multitude of different component sizes. Their travel paths range from 600 × 700 × 600 mm to 1,600 × 1,600 × 1,100 mm. Added to these are the DMC U models with pallet changers for higher productivity and increased spindle efficiency.

The duoBLOCK concept combines machining performance, precision and dynamics to a unique overall picture. Its rigidity is supported by extensive cooling measures ensuring that the high demands on accuracy required by aerospace customers can be fulfilled in the long term. The spindles available guarantee perfect performance: Both the 1,000 Nm and 77 kW powerMASTER 1000 motor spindle and the 5X torqueMASTER with its 1,800 Nm and 52 kW meet the demands of the aerospace industry to the full.

An optional highlight of the duoBLOCK models is the heavy-duty machining package. This comprises damping pads for the Y-axis, a hydraulic clamp on the NC rotary table and – in combination with a Siemens control – the heavy-duty machining ATC, a special DMG MORI technology cycle for this application. Taken all together this results in an up to 50 percent higher machining performance, in the case of materials that are difficult to machine to lower tool wear and better surface qualities.

Complete manufacturing in engine construction

“The technology integration of our mill-turn or turn-mill machines opens up the path to the process-stable complete machining of rotational symmetrical enginepartsmade of titanium or nickel alloys ”, explains Michael Kirbach. Leading manufacturers of engines such as GE Aviation, Rolls-Royce, Pratt & Whitney or MTU Aero Engines have in factbeen using the FD machines of the monoBLOCK, duoBLOCK and Portal series successfully for milling and turning in only a few setups for 18 years now.

Nowadays high-precision components can be produced even more productively thanks to further technology integrations. Even grinding wheels with internal and external cooling can, for example be changed over automatically with the FDS machines. Special DMG MORI technology cycles and structure-borne sound sensing help users with handling the technology. In addition systems for in-process measurement and integrated process monitoring support the operator on the path to the perfect process.

Michael Kirbach points out a trend towards the use of materials that are extremely difficult to machine, such as ceramic matrix composites (CMC), especially in the field of engine construction: “We have been working on these advanced materials for years. For such applications DMG MORI offers its LASERTEC and ULTRASONIC technology.” The focus here is always on expanding and improving conventional manufacturing processes. “It is not only important to be better and faster, but more cost-effective as well – e.g. by using ULTRASONIC to machine even materials such as CMC reliably and productively.”

Digitisation in the aerospace industry

The overall trend in the aerospace industry is towards the integral networking of machines, products and services to digital process chains. DMG MORI is also actively advancing the topic of digitisation with its “Path of Digitization”. All high-tech machines, for example, are equipped with the APP-based control and user interface CELOS. CELOS enables consistent management, documentation and planning of orders. In addition CELOS APPs such as “CONDITION ANALYZER” or “PERFORMANCE MONITOR” provide customers with a detailed view of the machining processes and the status of machines as the basis for a continuous improvement process. CELOS also functions to an ever greater extent as an IoT interface thus creating the basis for cross-company interaction in the production networks of the future.